Possible detections of stellar O VI in B-type spectra
Abstract
One goal of the Far Ultraviolet Spectroscopic Explorer (FUSE) mission is to study the formation of the O VI superion in the stellar winds of Galactic and Magellanic O- and B-type stars. As part of this ongoing effort, we have been analyzing FUSE spectra of a large number of early B-type stars, located both in the Galactic halo and the disk. The objective of this investigation is to determine how far into the domain of the B-type stars stellar O VI persists, and correlate its occurrence with other stellar parameters, particularly luminosity. By comparing the putative wind features in the O VI absorption with the N V, Si IV and C IV wind profiles seen in the IUE and STIS spectra, we have definitely identified wind features in the O VI absorption of three early B-type giants and supergiants (B0.5II-I, BN1Ib, B1II). Approximately half a dozen others show similar features that we could not yet clearly attribute to the wind. Our preliminary results suggest that the signatures of the wind in O VI appear in the spectra of giants and supergiants and not in the main-sequence B-type stars, at or near the terminal velocity of the wind. This work is based on observations made with the NASA-CNES-CSA Far Ultraviolet Spectroscopic Explorer. FUSE is operated for NASA by the Johns Hopkins University under NASA contract NAS5-32985.
- Publication:
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American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2001
- Bibcode:
- 2001AAS...19913510Z